Ultrasensitive sensors

Scientists create porous films––prepared using two different polymers and carbon nanotubes––that display remarkable sensitivity to changes in humidity levels and volatile organic compounds. 

These films, according to a new paper¹, take less than a second to respond to changes in humidity levels, overcoming limitations reported by scientists of films typically used in filtering molecules. The new films owe such fast response to the highly dense nanochannels with uniform pores on their surfaces.  

“The films can be used to make fast and sensitive sensors for vapour detection – an important phenomenon in various industries that make semiconductors, food and [are] involved in environmental monitoring,” says Md Azimul Haque, one of the researchers from the King Abdullah University of Science and Technology (KAUST), Saudi Arabia. 

To test their potential, scientists converted the films to sensors whose resistance decreased when humidity levels increased from 10% to 95% at room temperature. The sensors were found to run on low voltage. Such properties make the sensors fit for use in handheld battery-operated sensors, adds Haque.  

When exposed to prolonged and elevated levels of humidity, the sensors performed exceptionally well without losing their efficiency, according to the researcher, indicating a robust nature. 

Next, the researchers, led by Klaus-Viktor Peinemann and Tom Wu from KAUST, plan to redesign the sensors by attaching to them compounds made of sugars that should allow them to selectively detect specific molecules.

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